Pandemic Uncertainties and Next Steps

A contagion is clearly a complex phenomenon.  The way that the COVID-19 pandemic has affected different nations and the unique nature of the virus and its effects on the human body make for a very puzzling problem.  Added to this complexity is the fact that we are attempting to analyze and understand the contagion in real time with only limited historical data.

COVID-19 is clearly a dangerous contagion.  The virus, SAR-CoV-2, is much more contagious than the average flu and also appears to be about ten times as lethal. 

The fact that SARS-CoV-2 can create rampant outbreaks and huge challenges for healthcare systems with large numbers of resultant fatalities has been made clear in Wuhan, Italy, Spain, France, the UK and the U.S.  However, the pandemic has not yet had the devastating effect on developing nations that was expected, thankfully, and has been contained in some countries with relative ease – Sweden for example.

As we look forward to approaching summer in the U.S., there are several factors that seem to be critical in determining how things will develop from here:

Seasonality – Viruses are often seasonal.  The flu virus, which is also a coronavirus, has a distinct increase in its spread in winter and then more or less disappears in summer.  We do not know yet whether a virus as contagious as SARS-CoV-2 will be ‘seasonal’, but the fact that the contagion has seemed less dramatic in southern hemisphere countries may indicate that it is.  As far as I can tell, no one is quite certain why viruses are seasonal.  There may be many factors at play – the virus may be less viable at warmer temperatures, the way people interact changes, the air and atmosphere change, etc.  It is possible that summer will accelerate the decline of the contagion, which would certainly be welcome news.  But if that happens, then we would definitely have to be wary of a fall and winter resurgence.

Social Distancing Effect on Reproduction Number – Much of the U.S. avoided skyrocketing contagion by putting in place very restrictive social distancing measures, including the closing of restaurants, bars, businesses, stores, schools and most events.  Additionally, many people are now wearing masks.  Even with these measures, the reproduction number is just under 1.0 in most states.  The big question is whether relaxing many of these restrictions will cause the number to jump up (it has been estimated to be as high as 5.7 in some situations).  What is the ideal balance of social distancing and ‘open for business’?  We will probably have to experiment to discover the right mix, and hopefully we will not thrust ourselves right back into a catastrophic situation.

Antibody Effects and Immunity – People who have had COVID-19 have antibodies in their system.  Do these antibodies provide immunity to re-infection?  If so, for how long?  Will the immunity vary from person to person?  When a disease is rampaging in real-time these are the types of questions that are so difficult to answer.  Large amounts of data need to be gathered and analyzed to make any pronouncements.  The goal of herd immunity, where enough of the population has immunity to stop the spread of the disease (whether by vaccination or having had the disease) is highly desirable but not easily attained.

Health Risks of COVID-19 – The SARS-CoV-2 virus is very dangerous to the elderly and those with serious health problems such as obesity, diabetes, cardiovascular disease, high blood pressure, cancer and lung disease.  But it also occasionally strikes young, healthy individuals with dramatic effect, putting them in ICU’s on ventilators and sometimes killing them.  Yet, the virus can also be totally asymptomatic or have very minor symptoms, especially in the very young.  It takes time to understand all of the health impacts that a virus can have, and we will not understand all of the risks associated with allowing this virus to work its way through the world population for months if not years.  Another strange thing about this virus is that the very young rarely show significant symptoms and there are very few deaths in that age group, yet they are still a vector for transmission of the disease.

Testing and Tracking – The general trend of thinking in research groups and epidemiologists is that our only wise recourse in the interim period before a vaccine is available is to lower the number of active cases dramatically by continuing the strong restrictions that most countries have put in place.  Once the number of active cases is low, then a policy of aggressive testing, tracking and quarantine must be initiated to keep the contagion from re-surging.  If such a system is in place, then a reasonable level of ‘business as usual’ can be allowed.